Still run a couple old '5' series. Been my experience on raddle chains, when they start to cause trouble, replace the chain and sprockets. Don't have time or space to relate my 'lesson', but learned the hard way. Shoup has new chain only, so if you can save your slats, the cost is not out of sight. Checked their catalog and they also have complete chains. Shoup phone is 1-800-627-6137. Sprockets are still available from JD, at least two years ago. Check the grain conveyor bottoms and slip clutch. I know, its a can of worms, but when everything is right, they work like a charm. Good luck!